High-Yielding Enantioselective Synthesis of the Macrolactam Aglycon of Sch 38516 from Two Units of (2R)-2-Ethyl-4-penten-1-ol.

The same precursor-namely, (2R)-2-ethyl-4-penten-1-ol-was used to obtain fragments C9-C13 and C1-C8 of 1, the aglycon of Sch 38516 (which is active against Candida sp.) and fluvirucin B(1) (which is active against influenza A virus). The key steps of the synthesis were the aldol-like reaction between the two fragments and the macrolactamization of a 13-azidotridecanoic acid derivative (see scheme). MOM=methoxymethyl, Py=2-pyridyl.